/*
 * Copyright 2018-2020 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package dev.miku.r2dbc.mysql.message;

import io.netty.util.ReferenceCounted;

/**
 * An implementation of {@link FieldValue} considers field value is {@code null}.
 *
 * @see FieldValue
 */
final class NullFieldValue implements FieldValue {

    static final NullFieldValue INSTANCE = new NullFieldValue();

    private NullFieldValue() {
    }

    @Override
    public boolean isNull() {
        return true;
    }

    @Override
    public int refCnt() {
        return 1;
    }

    @Override
    public ReferenceCounted retain() {
        return INSTANCE;
    }

    @Override
    public ReferenceCounted retain(int increment) {
        return INSTANCE;
    }

    @Override
    public ReferenceCounted touch() {
        return INSTANCE;
    }

    @Override
    public ReferenceCounted touch(Object hint) {
        return INSTANCE;
    }

    @Override
    public boolean release() {
        return false;
    }

    @Override
    public boolean release(int decrement) {
        return false;
    }
}
